2001: An Air Quality Odyssey

April 8, 2026 by Bryan Cockfield 6 Comments

2001: A Space Odyssey not only pushed the boundaries of filmmaking, but introduced us to one of the most enduring villains in all of media. The HAL 9000 artificial intelligence was human-like but inhuman, a singular uncanny red light on a wall, tasked not only with control of a spaceship and its inner workings but also with being a companion for its occupants. It’s gone on to be the inspiration and basis of many projects around here, where it is generally given much less scope than control of a space ship and instead is tasked with something like monitoring air quality in a home.

Called the PAL 8000 by its creator [Arnov], this uses a Raspberry Pi Pico 2 at its core which monitors a volatile organic compound (VOC) sensor to take air quality measurements. The device features a custom 3D printed enclosure with glowing LEDs and plays contextual audio responses based on air quality levels, completing the HAL 9000 theme. The project also includes a local web dashboard which reports on its data, allowing users to see information in real time rather than relying on HAL’s voice reports alone.

For those looking to build other HAL-inspired projects, [Arnov] has made many of the printing files available on the project’s site. It’s a well-polished build faithful to the source material and could be a great addition to any home automation system for many other tasks beyond air quality monitoring. Perhaps something like a more general-purpose voice assistant, minus the megalomania.

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Overengineered Freezer Monitor Fills Market Void

May 19, 2025 by Bryan Cockfield 27 Comments

A lot of projects we see around here are built not just because they can be built, but because there’s no other option available. Necessity is the mother of invention, as they say. And for [Jeff] who has many thousands of dollars of food stowed in a chest freezer, his need for something to keep track of his freezer’s status was greater than any commercial offering available. Not only are freezers hard on batteries, they’re hard on WiFi signals as well, so [Jeff] built his own temperature monitor to solve both of these issues.

The obvious solution here is to have a temperature probe that can be fished through the freezer in some way, allowing the microcontroller, battery, and wireless module to operate outside of the harsh environment. [Jeff] is using K-type thermocouples here, wired through the back of the freezer. This one also is built into a block of material which allows him to get more diffuse temperature readings than a standard probe would provide. He’s also solving some other problems with commercially available probes here as well, as many of them require an Internet connection or store data in a cloud. To make sure everything stays local, he’s tying this in to a Home Assistant setup which also allows him to easily make temperature calibrations as well as notify him if anything happens to the freezer.

Although the build is very robust (or, as [Jeff] himself argues, overengineered) he does note that since he built it there have been some additional products offered for sale that fit this niche application. But even so, we always appreciate the customized DIY solution that avoids things like proprietary software, subscriptions, or cloud services. We also appreciate freezers themselves; one of our favorites was this restoration of a freezer with a $700,000 price tag.

FLOSS Weekly Episode 793: Keeping An Eye On Things With Hilight.io

July 24, 2024 by Jonathan Bennett No comments

This week Jonathan Bennett and Aaron Newcomb chat with Jay Khatri, the co-founder of Highlight.io. That’s a web application monitoring tool that can help you troubleshoot performance problems, find bugs, and improve experiences for anything that runs in a browser or browser-like environment. Why did they opt to make this tool Open Source? What’s the funding model? And what’s the surprising challenge we tried to help Jay solve, live on the show? Listen to find out!

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Automating 3D Printer Support Hardware

June 6, 2024 by Bryan Cockfield 22 Comments

While 3D printers have evolved over the past two decades from novelties to powerful prototyping tools, the amount of support systems have advanced tremendously as well. From rudimentary software that required extensive manual input and offered limited design capabilities, there’s now user-friendly interfaces with more features than you could shake a stick at. Hardware support has become refined as well with plenty of options including lighting, ventilation, filament recycling, and tool changers. It’s possible to automate some of these subsystems as well like [Caelestis Workshop] has done with this relay control box.

This build specifically focuses on automating or remotely controlling the power, enclosure lighting, and the ventilation system of [Caelestis Workshop]’s 3D printer but was specifically designed to be scalable and support adding other features quickly. A large power supply is housed inside of a 3D printed enclosure along with a Raspberry Pi. The Pi controls four relays which are used to control these various pieces hardware along with the 3D printer. That’s not the only thing the Pi is responsible for, though. It’s also configured to run Octoprint, a piece of open-source software that adds web interfaces for 3D printers and allows their operation to be monitored and controlled remotely too.

With this setup properly configured, [Caelestis Workshop] can access their printer from essentially any PC, monitor their prints, and ensure that ventilation is running. Streamlining the print process is key to reducing the frustration of any 3D printer setup, and this build will go a long way to achieving a more stress-free environment. In case you missed it, we recently hosed a FLOSS Weekly episode talking about Octoprint itself which is worth a listen especially if you haven’t tried this piece of software out yet.

Smart Garbage Trucks Help With Street Maintenance

August 24, 2023 by Zoe Skyforest 42 Comments

If you’ve ever had trouble with a footpath, bus stop, or other piece of urban infrastructure, you probably know the hassles of dealing with a local council. It can be incredibly difficult just to track down the right avenue to report issues, let alone get them sorted in a timely fashion.

In the suburban streets of one Australian city, though, that’s changing somewhat. New smart garbage trucks are becoming instruments of infrastructure surveillance, serving a dual purpose that could reshape urban management. Naturally, though, this new technology raises issues around ethics and privacy.

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Big Brother Or Dumb Brother? Bus Drivers In Beijing Are Forced To Wear “Emotional Monitors”

October 3, 2022 by Zoe Skyforest 64 Comments

Humans aren’t always great at respecting each other’s privacy. However, common sense says there’s a clear boundary when it comes to the thoughts in one’s own head and the feelings in one’s heart.

For bus drivers in Beijing though, it seems that’s no longer the case. These professional drivers are now being asked to wear emotional monitors while on the job, raising concerns from both legal and privacy advocates. But the devices aren’t really anything more than workout monitors, and whether they can actually make good on their Orwellian promise remains to be seen.

In Your Head, In Your Head!

The monitoring wristbands have been rolled out to some of Beijing’s long-distance bus drivers. Credit: Cypp0847, CC-BY-SA-4.0

When George Orwell wrote 1984, it was only 1949. However, he was able to foresee a world in which surveillance was omnipresent and inescapable. He also envsioned the concept of thoughtcrime, where simply contemplating the wrong things could get you in serious trouble with the authorities.

As we all know, Orwell was way off – these predictions didn’t become reality until well into the 2000s. In the latest horrifying development, technologies now exist that claim to be able to monitor one’s emotional state. Now, China’s transportation sector is rushing to push them on their workforces.

Long-distance bus drivers in Beijing are now being told to wear electronic wristbands when on the job. These wristbands claim to be able to capture the wearer’s emotional state, monitoring it on behalf of the employer. The scheme was the idea of the Beijing Public Transport Holding Group. The state-run organization claims the technology is intended for the safety of the public, and a trial of the wristbands began in July this year. Continue reading “Big Brother Or Dumb Brother? Bus Drivers In Beijing Are Forced To Wear “Emotional Monitors”” →

Low Power Weather Station Blows The Competition Away

May 3, 2019 by Bryan Cockfield 10 Comments

Building a weather station isn’t too tall of an order for anyone getting into an electronics project. There are plenty of plans online, and you can even put your station on Weather Underground if it meets certain standards. These usually have access to a reliable source of power, though, and like any electronics project can get challenging quickly once it needs to work reliably in a remote location. The weather station from [Tegwyn☠Twmffat] has met this challenge though, and has been working reliably for three years now.

Getting that sort of reliability from any circuit that has to be powered by an unreliable source (solar, wind, etc.) and a battery is quite a challenge. Not only do you need to sort out the power management and make sure that you can get enough sun in the winter for your application, but you’ll need to do some extreme low power modifications to your circuitry as well. This weather station accomplishes all of that, helped by using LoRa for communication, and also comes complete with a separate hardware watchdog timer that can reboot the weather station if it loses power or hangs up for some reason.

If you’ve been looking for a weather station to build, this is a great place to start. [Tegwyn☠Twmffat] also goes through the assembly of the weather station, complete with a guy-wire-supported platform to mount it on. There are other weather stations out there too, if you need even more ideas about saving power in remote areas.